oracle system表空间的管理

1、空间管理（字典所在，定义信息，不放用户数据）
单个数据文件即可
设置自动扩展，设置bigfile
2、system如何备份
必须归档下才能在open下完成备份
a、热备 b、rman备
非归档下只能进行冷备
使用archive log list命令查看数据库是否为归档模式：

SQL> archive log listDatabase log mode              Archive ModeAutomatic archival             EnabledArchive destination            USE_DB_RECOVERY_FILE_DESTOldest online log sequence     1Next log sequence to archive   1Current log sequence           1

热备操作：
SQL> alter tablespace system begin backup;

Tablespace altered.SQL> ho cp /u01/app/oracle/oradata/orcl/system01.dbf /u01/app/oracle/bak/system01.dbfSQL> alter tablespace system end backup;Tablespace altered.

RMAN备操作:

[oracle@oracle11g bak]$ rman target /Recovery Manager: Release 11.2.0.1.0 - Production on Mon Apr 24 11:48:48 2017Copyright (c) 1982, 2009, Oracle and/or its affiliates.  All rights reserved.connected to target database: ORCL (DBID=1445346880)RMAN> backup tablespace system;Starting backup at 24-APR-17using target database control file instead of recovery catalogallocated channel: ORA_DISK_1channel ORA_DISK_1: SID=17 device type=DISKchannel ORA_DISK_1: starting full datafile backup setchannel ORA_DISK_1: specifying datafile(s) in backup setinput datafile file number=00001 name=/u01/app/oracle/oradata/orcl/system01.dbfchannel ORA_DISK_1: starting piece 1 at 24-APR-17channel ORA_DISK_1: finished piece 1 at 24-APR-17piece handle=/u01/app/oracle/flash_recovery_area/ORCL/backupset/2017_04_24/o1_mf_nnndf_TAG20170424T114901_dhtxfg5p_.bkp tag=TAG20170424T114901 comment=NONEchannel ORA_DISK_1: backup set complete, elapsed time: 00:00:55channel ORA_DISK_1: starting full datafile backup setchannel ORA_DISK_1: specifying datafile(s) in backup setincluding current control file in backup setincluding current SPFILE in backup setchannel ORA_DISK_1: starting piece 1 at 24-APR-17channel ORA_DISK_1: finished piece 1 at 24-APR-17piece handle=/u01/app/oracle/flash_recovery_area/ORCL/backupset/2017_04_24/o1_mf_ncsnf_TAG20170424T114901_dhtxh8g7_.bkp tag=TAG20170424T114901 comment=NONEchannel ORA_DISK_1: backup set complete, elapsed time: 00:00:01Finished backup at 24-APR-17RMAN> 

3、system表出现问题，如何恢复
a、归档 有备份 日志完整 可以恢复
b、归档 有备份 日志不完整 可以恢复，不能保证数据不丢失

热备恢复：SQL> startupORACLE instance started.Total System Global Area  835104768 bytesFixed Size                  2217952 bytesVariable Size             624953376 bytesDatabase Buffers          205520896 bytesRedo Buffers                2412544 bytesDatabase mounted.ORA-01157: cannot identify/lock data file 1 - see DBWR trace fileORA-01110: data file 1: '/u01/app/oracle/oradata/orcl/system01.dbf'SQL> ho cp /u01/app/oracle/oracle/bak/system01.dbf /u01/app/oracle/oradata/orcl/system01.dbfSQL> alter database open;alter database open*ERROR at line 1:ORA-01113: file 1 needs media recoveryORA-01110: data file 1: '/u01/app/oracle/oradata/orcl/system01.dbf'SQL> recover database;Media recovery complete.SQL> alter database open;Database altered.

RMAN备恢复：

SQL> startup;    ORACLE instance started.Total System Global Area  835104768 bytesFixed Size                  2217952 bytesVariable Size             624953376 bytesDatabase Buffers          205520896 bytesRedo Buffers                2412544 bytesDatabase mounted.ORA-01157: cannot identify/lock data file 1 - see DBWR trace fileORA-01110: data file 1: '/u01/app/oracle/oradata/orcl/system01.dbf'SQL> exitDisconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit ProductionWith the Partitioning, OLAP, Data Mining and Real Application Testing options[oracle@oracle11g ~]$ rman target /Recovery Manager: Release 11.2.0.1.0 - Production on Mon Apr 24 12:48:15 2017Copyright (c) 1982, 2009, Oracle and/or its affiliates.  All rights reserved.connected to target database: ORCL (DBID=1445346880, not open)RMAN> list backup;using target database control file instead of recovery catalogList of Backup Sets===================BS Key  Type LV Size       Device Type Elapsed Time Completion Time------- ---- -- ---------- ----------- ------------ ---------------1       Full    588.09M    DISK        00:00:36     19-APR-17              BP Key: 1   Status: AVAILABLE  Compressed: NO  Tag: TAG20170419T115143        Piece Name: /u01/app/oracle/flash_recovery_area/ORCL/backupset/2017_04_19/o1_mf_nnndf_TAG20170419T115143_dhfqphqg_.bkp  List of Datafiles in backup set 1  File LV Type Ckp SCN    Ckp Time  Name  ---- -- ---- ---------- --------- ----  1       Full 1044250    19-APR-17 /u01/app/oracle/oradata/orcl/system01.dbfBS Key  Type LV Size       Device Type Elapsed Time Completion Time------- ---- -- ---------- ----------- ------------ ---------------2       Full    9.36M      DISK        00:00:04     19-APR-17              BP Key: 2   Status: AVAILABLE  Compressed: NO  Tag: TAG20170419T115143        Piece Name: /u01/app/oracle/flash_recovery_area/ORCL/backupset/2017_04_19/o1_mf_ncsnf_TAG20170419T115143_dhfqr17l_.bkp  SPFILE Included: Modification time: 19-APR-17  SPFILE db_unique_name: ORCL  Control File Included: Ckp SCN: 1044266      Ckp time: 19-APR-17BS Key  Type LV Size       Device Type Elapsed Time Completion Time------- ---- -- ---------- ----------- ------------ ---------------3       Full    589.84M    DISK        00:00:41     20-APR-17              BP Key: 3   Status: AVAILABLE  Compressed: NO  Tag: TAG20170420T142552        Piece Name: /u01/app/oracle/flash_recovery_area/ORCL/backupset/2017_04_20/o1_mf_nnndf_TAG20170420T142552_dhjo3jv0_.bkp  List of Datafiles in backup set 3  File LV Type Ckp SCN    Ckp Time  Name  ---- -- ---- ---------- --------- ----  1       Full 1089734    20-APR-17 /u01/app/oracle/oradata/orcl/system01.dbfBS Key  Type LV Size       Device Type Elapsed Time Completion Time------- ---- -- ---------- ----------- ------------ ---------------4       Full    9.36M      DISK        00:00:01     20-APR-17              BP Key: 4   Status: AVAILABLE  Compressed: NO  Tag: TAG20170420T142552        Piece Name: /u01/app/oracle/flash_recovery_area/ORCL/backupset/2017_04_20/o1_mf_ncsnf_TAG20170420T142552_dhjo4z8l_.bkp  SPFILE Included: Modification time: 20-APR-17  SPFILE db_unique_name: ORCL  Control File Included: Ckp SCN: 1093814      Ckp time: 20-APR-17BS Key  Type LV Size       Device Type Elapsed Time Completion Time------- ---- -- ---------- ----------- ------------ ---------------5       Full    593.09M    DISK        00:00:49     24-APR-17              BP Key: 5   Status: AVAILABLE  Compressed: NO  Tag: TAG20170424T114901        Piece Name: /u01/app/oracle/flash_recovery_area/ORCL/backupset/2017_04_24/o1_mf_nnndf_TAG20170424T114901_dhtxfg5p_.bkp  List of Datafiles in backup set 5  File LV Type Ckp SCN    Ckp Time  Name  ---- -- ---- ---------- --------- ----  1       Full 1268534    24-APR-17 /u01/app/oracle/oradata/orcl/system01.dbfBS Key  Type LV Size       Device Type Elapsed Time Completion Time------- ---- -- ---------- ----------- ------------ ---------------6       Full    9.36M      DISK        00:00:03     24-APR-17              BP Key: 6   Status: AVAILABLE  Compressed: NO  Tag: TAG20170424T114901        Piece Name: /u01/app/oracle/flash_recovery_area/ORCL/backupset/2017_04_24/o1_mf_ncsnf_TAG20170424T114901_dhtxh8g7_.bkp  SPFILE Included: Modification time: 24-APR-17  SPFILE db_unique_name: ORCL  Control File Included: Ckp SCN: 1268564      Ckp time: 24-APR-17RMAN> restore tablespace system;Starting restore at 24-APR-17allocated channel: ORA_DISK_1channel ORA_DISK_1: SID=18 device type=DISKchannel ORA_DISK_1: starting datafile backup set restorechannel ORA_DISK_1: specifying datafile(s) to restore from backup setchannel ORA_DISK_1: restoring datafile 00001 to /u01/app/oracle/oradata/orcl/system01.dbfchannel ORA_DISK_1: reading from backup piece /u01/app/oracle/flash_recovery_area/ORCL/backupset/2017_04_24/o1_mf_nnndf_TAG20170424T114901_dhtxfg5p_.bkpchannel ORA_DISK_1: piece handle=/u01/app/oracle/flash_recovery_area/ORCL/backupset/2017_04_24/o1_mf_nnndf_TAG20170424T114901_dhtxfg5p_.bkp tag=TAG20170424T114901channel ORA_DISK_1: restored backup piece 1channel ORA_DISK_1: restore complete, elapsed time: 00:00:45Finished restore at 24-APR-17RMAN> recover tablespace system;Starting recover at 24-APR-17using channel ORA_DISK_1starting media recoverymedia recovery complete, elapsed time: 00:00:00Finished recover at 24-APR-17RMAN> sql 'alter database open';sql statement: alter database open

4、system表空间不可只读、不可脱机

SQL> alter tablespace system read only  2  ;alter tablespace system read only*ERROR at line 1:ORA-01643: system tablespace can not be made read-onlySQL> alter tablespace system offline;alter tablespace system offline*ERROR at line 1:ORA-01541: system tablespace cannot be brought offline; shut down if necessarySQL>